Following tests both as a floatplane and with a conventional wheeled undercarriage, production orders were placed for two versions both powered by the Maori, the IIIA and IIIB, with 50 and 60 aircraft planned, respectively. The Fairey IIIA was a reconnaissance aircraft intended to operate from aircraft carriers, and as such was fitted with a wheeled or skid undercarriage, while the IIIB was intended as a floatplane bomber, with larger span (increased from 46 ft 2 in/14.19 m to 62 ft 9 in/19.13 m) upper wings and a bombload of three 230 lb (105 kg) bombs.[2] While all 50 IIIAs were built, only 28 of the IIIBs were completed as intended, as a new improved bomber/reconnaissance floatplane, the Fairey IIIC was available, of which 36 were produced, which reverted to short equal-span wings like the IIIA but was powered by the much more powerful and reliable 375 hp (280 kW) Rolls-Royce Eagle VIII engine and could still carry a useful bombload. Many of the IIIBs were completed as IIICs.[3]

The first major production model was the IIID, which was an improved IIIC, with provision for a third crewmember and capable of being fitted with either a floatplane or a conventional wheeled undercarriage.[4] It first flew in August 1920,[5] powered by a Rolls-Royce Eagle, and initial production for the Fleet Air Arm, together with aircraft produced for Australia and Portugal retained the Eagle, while later aircraft were powered by the more powerful Napier Lion.[5] The naval variants were usually three-seaters; pilot, observer and gunner and the wings would could be folded back parallel to the fuselage for storage aboard ship. In floatplane configuration, carrier-borne Fairey IIIs would be launched from the deck using a trolley and would land on the water upon their return. The Fairey III floatplane could also be catapult-launched from a ship. The IIID had a wooden, fabric-covered fuselage and usually a wooden, two-blade, fixed-pitch propeller. One IIID was built with metal wings and floats. A total of 207 IIIDs were produced for the Fleet Air Arm and RAF (Royal Air Force), with a further 20 being built for export.[5]

A Fairey III floatplane (G-EALQ) with a 450 hp Napier Lion was entered into the Air Ministry Commercial Amphibian Competition of September 1920.[6]

The most prolific and enduring of the Fairey IIIs was the final model, the IIIF, which was designed to meet Air Ministry Specification 19/24 for a three-seat spotter/reconnaissance aircraft for the Fleet Air Arm and a two-seat general purpose aircraft for the Royal Air Force. The IIIF, which first flew on 20 April 1926,[7] had a more streamlined engine installation and initially a fuselage of mixed metal and wooden construction, with similar wings to the IIID, although later production aircraft were fitted with an all-metal fuselages and wings.[8]

Over 350 IIIFs were operated by the Fleet Air Arm, making it the most widely used type of aircraft in Fleet Air Arm service between the wars.[9] In fact, of the British military aircraft in the inter-war years, only the Hawker Hart family was produced in greater numbers.[10]

Three IIIFs were modified as a radio-controlled gunnery trainer, known as the Fairey Queen. The Fairey IIIF was also the basis for development of the Gordon and Seal.

The IIIA and IIIB saw limited service towards the end of the war, with some IIIBs being used for mine-spotting duty from the seaplane station at Westgate-on-Sea.[11] The IIIC entered service in November 1918, but did not carry out any combat patrols owing to the Armistice ending hostilities with Germany. Seven IIICs were deployed to Arkhangelsk in 1919 by the seaplane tenderHMS Pegasus in support of the North Russian Expeditionary Force. They were used to carry out bombing attacks against Bolshevik shipping and rail communications.[12]

Fairey IIID floatplane during a circumnavigation of Australia in 1924.

Australia received six IIIDs, the first being delivered in August 1921. In 1924, the third of the Australian IIIDs, designated ANA.3 (or Australian Naval Aircraft No. 3), flown by Stanley Goble (later Air Vice Marshal) and Ivor McIntyre was awarded the Britannia Trophy by the Royal Aero Club for circumnavigating Australia in 44 days. The IIID remained in Australian service until 1928.[13]

Portugal ordered its first IIIDs in 1921. Its first aircraft, modified as the F.400 and named "Lusitânia", was used for an attempt to fly across the South Atlantic and demonstrate the new aerial navigation system devised by Gago Coutinho, the navigator. The voyage started on 30 March 1922 (Flyers Day in Portugal), stopping at Las Palmas, São Vicente, Cape Verde and achieving the main navigation goal of Saint Peter and Paul Rocks, where it was lost during refuel.[14] The journey was finished using another two standard aircraft (the second of which was immediately lost in the sea), completing the first aerial crossing of the South Atlantic, 72 days after their departure from Lisbon. The last aircraft, "Santa Cruz", is currently displayed at the Museu de Marinha, in Portugal.

The IIID entered Fleet Air Arm Service in 1924, operating from shore bases, aircraft carriers and floats until replaced by the IIIF in 1930. The RAF Cape Flight used four IIIDs to carry out a long distance formation flight from Cairo to Cape Town and back in 1926, the first long range formation flight by the RAF and the first RAF flight to South Africa.[15] Fleet Air Arm IIIDs were used to defend British interests in Shanghai against rebel Chinese forces in 1927.[16]

The IIIF entered service with the RAF in Egypt and with Fleet Air Arm Catapult flights in 1927,[17][18] and with the Royal New Zealand Air Force shortly after. The RAF used the IIIF to equip general-purpose squadrons in Egypt, Sudan, Aden and Jordan, where its ability to operate from both wheels and floats proved useful, while the contemporary Westland Wapiti carried out similar roles in Iraq and India.[19] As such IIIFs were used for colonial policing as well as taking part in further long distance flights. The RAF also used the IIIF to finally replace the Airco DH.9A in the home based Day-Bomber role, and, in the absence of sufficient long range flying boats for maritime patrol duties by 202 Squadron from Hal FarMalta.[20]

The IIIF remained in front line service well into the 1930s, with the last front line RAF squadron, 202 Squadron, re-equipping with Supermarine Scapas in August 1935,[22] and the final front line Fleet Air Arm squadron, 822 Squadron retained the IIIF until 1936.[23] The IIIF remained in use in second line roles, and despite being declared obsolete in 1940,[24] some were still in use as target tugs as late as 1941.[25]

The first prototype III was purchased back by Fairey in 1919, fitted with new, single bay wings and a Napier Lion engine and entered into the 1919 Schneider Trophy race, on 10 September. The race was abandoned due to fog, however.[26]

Four IIICs were civilianized, some with an extra cockpit between the two standard ones and sometimes with an enlarged rear cockpit. One carried five passengers, one in the extra cockpit and four in the rear.[27] One three seat civilianized IIIC (G-EBDI) was part of a Daily News sponsored multi-aircraft round the world flight in 1922, with Norman Macmillan, W.T. Blake and cine-photographer G.H. Malins. The aircraft, with Macmillan and Malins aboard was finally lost between Lakhidia Char and Chittagong, but the crew were rescued.[28]

A small number of civil operated IIIDs and IIIFs were used for survey duties in the 1920s and 30s, while in October 1934 a single IIIF was entered into the MacRobertson Air Race, reaching the finishing line in Melbourne but too late to be classed as completing the race.[29]

A single example of the Fairey III is preserved in Portugal's Museu de Marinha (Naval Museum). This is the airplane that finished the first aerial crossing of the South Atlantic. The British Fleet Air Arm Museum has a fuselage.

The first IIID (manufacturers serial number F.400) for the Portuguese Navy was delivered as a special long-range variant with an extended wing-span of 61 feet. It was also referred to as the Fairey Transatlantic and given the name Luzitania when it was used for an attempt to fly across the South Atlantic in 1922, stopping at Las Palmas, São Vicente, Cape Verde before being lost making a refuelling stop at the Saint Peter and Paul Rocks.[14]

Argentine Naval Aviation - Purchased six IIIF MkIIIM (Special) powered by 450 hp (336 kW) Lorraine Dietrich Ed12 engine in 1928. They entered service in 1929. The remaining aircraft were re-engined with Armstrong Siddeley Panthers in 1935, with the last aircraft being retired in 1942.[34]